UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS 

COLLEGE  OF  AGRICULTURE 

AGRICULTURAL   EXPERIMENT   STATION 

BERKELEY.   CALIFORNIA 


GROWING  AND  HANDLING 
ASPARAGUS  CROWNS 


BY 

H.  A.  JONES  AND  W.  W.  ROBBINS 


BULLETIN  No.  381 

December,  1924 


UNIVERSITY  OF  CALIFORNIA  PRINTING  OFFICE 

BERKELEY,  CALIFORNIA 

1924 


GROWING  AND  HANDLING  ASPARAGUS  CROWNS 

By  H.  A.  JONES  and  W.  W.  BOBBINS 


CONTENTS  PAGE 

Growing  versus  buying  crowns 4 

Types  of  soil 5 

Preparation  of  seed  bed 5 

Seed  selection 6 

Age  of  plants  from  which  to  select  seed 6 

Quality  of  seed  from  different  parts  of  the  plant 6 

Selecting  and  handling  plants  for  seed  production 7 

Harvesting  and  grading  seed .' 8 

Seed  treatment 9 

Planting  season 11 

Varieties 11 

Seeding 12 

Rate  of  seeding 12 

Methods  of  planting 12 

Intercropping 12 

Depth  of  planting 13 

Germination  of  seeds 13 

Description  of  berry  and  seed 13 

Germination  processes 14 

Conditions  necessary  for  germination 17 

Rate  of  germination 18 

Development  of  the  plant  during  first  season  of  growth 20 

Sex  expression  in  the  nursery 26 

Thinning 26 

Irrigation 28 

Cultivation 28 

Digging  the  crowns 29 

Sorting  and  grading  crowns 34 

At  present  California  stands  preeminent  in  asparagus  production. 
The  most  concentrated  asparagus-growing  area  is  located  in  the  Delta 
region,  including  the  ' '  reclaimed ' '  low  lands  of  the  lower  Sacramento 
and  San  Joaquin  rivers.  The  Imperial  Valley  has  also  grown  a  con- 
siderable acreage  of  asparagus  for  a  number  of  years,  from  which 
early  shipments  are  made  to  the  Middle  West  and  the  Eastern 
markets.  Small  acreages  are  to  be  found  in  other  sections  of  the 
state.  Most  of  the  asparagus  is  grown,  however,  in  the  hot  interior 
valleys  like  the  Sacramento,  San  Joaquin,  Imperial,  and  San  Fer- 
nando, because  along  the  coast  the  lower  average  temperatures  make 
asparagus  production  unprofitable. 


4  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Asparagus  growing  has  increased  generally  over  the  entire  country 
during  the  last  few  years,  but  in  California  the  increase  in  acreage 
has  been  greater  than  in  any  other  state.  The  present  indications  are 
that  the  acreage  will  continue  to  increase  for  a  number  of  years, 
especially  in  those  sections  where  the  crop  is  grown  for  canning  pur- 
poses. It  will  be  necessary  to  grow  sufficient  crowns  to  plant  this 
additional  acreage  and  also  to  replace  the  old  plantations  that  are 
plowed  up  each  year  because  of  ageing.  The  profitable  life  of  an 
asparagus  bed  in  the  Delta  region  is  about  twelve  years.  In  some 
sections  it  appears  to  be  somewhat  longer,  but  if  the  acreage  is  to  be 
maintained,  approximately  one  twelfth  of  it  must  be  replanted  each 
year. 

This  bulletin  contains  a  number  of  contributions  to  our  knowledge 
of  the  growth  habits  of  asparagus  which  bear  upon  the  production 
and  handling  of  crowns.  Other  material  more  or  less  generally  known 
to  experienced  asparagus  growers  is  included  in  order  to  make  the 
bulletin  of  more  service  to  those  who  have  had  little  or  no  experience 
in  the  growing  and  handling  of  crowns. 

GROWING    VERSUS    BUYING    CROWNS 

Commercial  asparagus  growers  generally  grow  their  own  one  year 
old  crowns.  There  are  several  reasons  for  doing  this:  (1)  It  usually 
costs  less  to  grow  crowns  than  to  buy  them.  This  applies  especially 
to  large  acreages  such  as  are  usual  when  asparagus  is  grown  for  can- 
ning or  as  a  truck  crop.  Freight  charges  are  high  on  the  most  desir- 
able crowns  which  are  bulky  and  heavy.  (2)  The  grower  has  in- 
formation regarding  the  seed.  When  he  produces  his  own  seed,  he  is 
familiar  with  the  variety  and  performance  of  the  beds  from  which 
the  seed  has  been  obtained.  Seed  for  planting  the  nursery  may  be 
obtained  from  reliable  sources,  either  firms,  or  individuals,  who  know 
the  principles  of  selection  and  give  special  attention  to  the  improve- 
ment of  this  crop.  Since  the  yields  from  asparagus  extend  over  a 
period  of  ten  or  twelve  years,  extra  effort  can  well  be  expended  in 
securing  the  best  seed.  Using  cheap  seed  is  not  economy.  (3)  There 
is  opportunity  for  rigorous  crown  selection.  Even  under  conditions 
conducive  to  the  best  crown  development  some  grading  should  be 
made.  Consequently,  it  is  necessary  to  grow  a  surplus  so  that  there 
will  be  a  si. Hi  .'cut  number  of  good  crowns  for  planting.  Some 
nurserymen  and  seedsmen  sell  only  the  best  crowns,  but  as  a  general 
rule  Ihey  do  very  little  grading.  (4)  Delayed  planting  can  be 
avoided.    The  best  results  are  obtained,  as  regards  immediate  growth 


BULLETIN    381]  GROWING   AND    HANDLING   ASPARAGUS    CROWNS  5 

and  perfect  stand,  if  the  crowns  are  set  shortly  after  digging.  (5) 
Climatic  conditions  in  California  are  conducive  to  good  crown  devel- 
opment. On  account  of  the  long  growing  season  and  the  great  amount 
of  sunshine  prevalent  during  the  spring,  summer  and  early  fall, 
plants  make  a  greater  growth  in  one  season  in  California  than  in 
most  parts  of  the  country.  For  these  reasons  it  is  deemed  highly 
desirable  that  growers  raise  their  own  crowns. 

If  only  a  few  crowns  are  to  be  planted  as  in  the  case  of  the  home 
garden,  it  is  usually  cheaper  to  buy  them  from  a  reliable  nurseryman. 
The  buyer  should  specify  that  only  well-developed  one-year-old 
crowns  will  be  accepted. 

TYPES   OF  SOIL 

Good  asparagus  crowns  can  be  grown  on  soils  of  various  types. 
The  best  soils,  however,  for  the  production  of  nursery  stock  are 
well-decomposed  peat,  or  light,  sandy  loam.  These  soils  are  open  and 
porous  and  facilitate  root  penetration  and  elongation.  One  of  the 
most  important  reasons  for  choosing  light  soils  for  the  nursery  is 
that  crowns  may  be  dug  with  a  minimum  of  injury.  Excellent  crowns 
can  be  produced  on  light  sandy  soils  if  fertilizers  and  a  sufficient 
amount  of  water  are  applied. 

Heavy  soils  can  be  used  for  the  growing  of  crowns,  but  they  are 
not  so  desirable  as  the  lighter  types.  A  great  amount  of  labor  is 
required  to  keep  such  soils  in  good  physical  condition.  They  usually 
remain  wet  till  late  spring,  especially  in  regions  of  heavy  winter 
rainfall,  and  they  warm  up  more  slowly  than  the  lighter  soils,  thus 
delaying  germination  and  retarding  the  growth  of  the  plant  after 
germination.  Since  heavy  soils  become  packed,  it  is  difficult  to  dig 
the  crowns  without  injuring  many  of  the  rootstocks  and  losing  a  large 
percentage  of  the  fleshy  roots.  As  these  roots  contain  the  reserve 
food  supply,  their  loss  is  bound  to  weaken  the  early  growth  of  the 
plant. 

PREPARATION    OF   THE    SEED    BED 

Land  that  is  sub-irrigated  should  be  practically  level  so  that 
uniform  moisture  conditions  can  be  maintained.  On  surface  irri- 
gated land  a  slight  fall  is  necessary.  The  land  should  be  compara- 
tively free  from  clods.  A  fine,  well  pulverized  seed  bed  permits  the 
soil  particles  to  come  into  close  contact  with  the  seed,  insuring  a 
constant  water  supply  and  rapid  germination. 

It  is  well  known  that  asparagus  seed  germinates  slowly.  Conse- 
quently, weeds  often  make  sufficient  growth  to  hide  the  young  aspara- 


6  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

gus  plants  before  they  are  large  enough  to  be  seen  in  the  row  and 
cultivated.  A  weedy  asparagus  nursery  requires  much  labor  and 
expense  and  may  result  in  inferior  crowns.  Special  care  should  be 
taken  to  select  land  that  is  comparatively  free  from  weeds. 

SEED    SELECTION 

It  is  well  recognized  by  all  asparagus  growers  that  large,  plump, 
glossy  and  fully  matured  seed  is  superior  to  small,  shriveled,  dull  and 
immature  seed.  However,  the  methods  of  growing  asparagus  seed 
of  high  quality  have  not  been  given  the  attention  that  they  deserve. 

Age  of  Plant  from  which  to  Select  Seed. — There  is  a  diversity  of 
opinion  among  growers  as  to  what  the  ages  of  plants  should  be  in 
order  to  yield  seed  of  the  best  quality.  The  statement  is  made  by 
some  that  plants  must  be  "not  less  than  four  years  old"  before  they 
have  sufficient  maturity  and  vigor  to  produce  seed  of  high  quality. 
Other  growers  state  that  seed  should  be  harvested  only  from  plants, 
the  crowns  of  which  were  planted  the  previous  year.  The  reason 
given  for  the  latter  advice  is  that  plants  of  this  age  have  not  been 
"weakened"  by  the  harvesting  of  sprouts  during  the  current  year 
to  the  extent  that  older  plants  have,  and  "consequently  it  has  been 
possible  for  more  energy  to  be  directed  to  the  production  of  seed." 
In  explanation  of  this  claim,  it  should  be  stated  that  it  is  a  common 
practice  on  California  asparagus  farms  to  cut  market  asparagus  for 
a  period  of  about  three  or  four  weeks  the  first  year  after  transplanting  ; 
whereas,  in  older  beds,  the  cutting  season  is  for  a  much  longer  period. 
Hence,  in  the  former  case,  there  is  a  longer  season  of  growth  after 
the  cutting  period  than  in  the  older  beds.  It  is  reasoned  that  seed 
from  plants  which  have  been  cut  for  a  few  weeks  only  will  have  a 
better  opportunity  to  fill  out  and  mature. 

It  should  be  stated  also  that  by  taking  seed  from  young  asparagus 
beds,  rather  than  from  old  ones,  the  grower  has  a  better  opportunity 
to  make  rapid  improvement  in  his  varieties. 

Other  growers  claim  that  there  is  no  correlation  between  the  age 
of  the  mother  plant,  and  the  vigor  of  the  seed  it  produces. 

Unfortunately,  there  are  no  reliable  experimental  data  which  will 
enable  us  to  discuss  authoritatively  the  three  views  presented  above 
and  In  make  a  definite  recommendation  as  to  the  best  age  of  plants 
from  which  to  select  seed. 

(Jimlity  of  Seed  from  Different  Parts  of  the  Plant. — Some  hold 
the  opinion  that  seed  borne  on  different  parts  of  the  same  plant 
Varies  in  quality.     It  is  stated  that  the  best  seed  is  procured  from 


BULLETIN   381]  GROWING   AND    HANDLING   ASPARAGUS    CROWNS  7 

the  lower  part  of  the  plant  and  that  consequently  it  is  advisable  to 
top  the  plant  by  removing  from  eight  to  twelve  inches  after  the 
basal  flowers  have  been  fertilized.  The  first  flowers  to  open  and  the 
first  berries  to  form  are  on  the  main  shoot  near  the  base  of  the  plant ; 
and  considering  the  whole  plant,  or  any  one  branch,  the  order  of 
maturing  of  berries  is  from  the  base  to  the  apex.  At  the  tips  of  the 
branches,  then,  there  may  be  at  harvest  time  a  considerable  number 
of  berries  which  are  not  so  well  developed  as  those  farther  down  on 
the  branches,  and  consequently  the  harvested  seed  may  contain  a 
certain  percentage  of  seed  from  relatively  immature  berries.  It  is 
believed  that  this  condition  can  be  obviated  by  cutting  back  the  tops 
after  the  basal  flowers  have  been  fertilized.  It  is  also  asserted  that 
topping  the  plants  leaves  more  nourishment  available  for  the  remain- 
ing seeds,  and  that  they  will  thereby  become  larger  and  produce  more 
vigorous  seedlings. 

Since  no  carefully  conducted  tests  have  been  made  to  ascertain 
the  value  of  the  practice  of  cutting  back  the  tops  of  seed-bearing 
plants,  the  authors  are  not  in  a  position  either  to  recommend  or  dis- 
courage this  practice.  It  appears,  however,  that  careful  screening 
and  grading  will  eliminate  the  smaller  and  less  mature  seeds,  which 
are  borne  near  the  tops  of  the  branches.  Grading  is  suggested  as 
being  a  possible  and  desirable  substitute  for  topping. 

Selecting  and  Handling  Plants  for  Seed  Production. — The  com- 
mercial grower  who  is  producing  his  own  seed,  should  observe  some 
of  the  fundamental  principles  of  selection.  With  most  of  our  crops, 
both  male  and  female  reproductive  organs  occur  on  the  same  plant 
and  usually  in  the  same  flower,  but  each  asparagus  plant  is  of  one 
sex  only.  That  is,  any  one  asparagus  plant  will  produce  either 
pollen-bearing  flowers  only  or  seed-bearing  flowers  only.  We  speak 
of  pollen-bearing  plants  as  male  or  staminate  and  seed-bearing  plants 
as  female  or  pistillate.  In  the  ordinary  commercial  field  approxi- 
mately equal  numbers  of  male  and  female  plants  occur.  It  is  as 
important,  therefore,  to  choose  the  best  male  plants  as  it  is  to  select 
productive,  healthy,  and  desirable  types  of  female  plants. 

The  improvement  of  asparagus  by  seed  selection  is  an  attractive 
undertaking  and  will  prove  profitable  if  done  properly.  Several 
methods  are  suggested  below : 

(1)  Records  of  the  performance  of  certain  promising  individual 
crowns  should  be  kept  over  a  period  of  several  years.  The  crowns 
of  the  most  desirable  male  and  female  plants  should  be  dug  and  set 
together  in  a  bed  that  is  isolated.     One  male  plant  to  about  five  or 


8  UNIVERSITY    OF    CALIFORNIA — :EXPERIMENT    STATION 

six  females  is  sufficient.  It  is  best  to  group  the  female  plants  about 
the  male.  The  desirable  female  plants  will  be  pollinated  only  by  the 
selected  males.  The  resulting  seed  may  be  planted  and  the  qualities 
of  the  progeny  tested. 

(2)  In  the  commercial  field,  a  number  of  the  most  desirable  male 
and  female  individual  plants  should  be  marked  in  the  ratio  of  approx- 
imately one  male  to  five  or  six  females.  These  individuals  should 
be  fairly  close  together  in  order  that  pollen  may  be  carried  from  the 
male  plants  to  the  female  plants.  These  marked  individuals  should 
be  allowed  to  mature  before  the  main  crop,  so  that  pollination  is  only 
between  the  individuals  selected.  The  seed  should  be  harvested  and 
the  progeny  tested. 

(3)  A  small  isolated  acreage  should  be  set  aside  for  seed  pro- 
duction only.  At  the  beginning  of  blooming  time  the  grower  should 
grub  out  weak  and  undesirable  types  of  male  plants.  If  they  are 
left  in  the  field,  pollen  from  them  may  be  carried  to  the  flowers  of 
the  selected  female  plants  and  the  undesirable  characters  of  the 
inferior  males  will  be  transmitted  to  the  progeny  of  the  superior 
females.  Seed  from  only  the  superior  females  should  be  harvested. 
It  is  unnecessary  to  grub  out  the  inferior  females,  the  seed  of  which 
should  not  be  harvested. 

Both  male  and  female  plants  for  seed  production  should  be  selected 
only  from  those  whose  stalks  are  uniformly  tall  and  about  one  inch 
in  diameter,  and  whose  branches  do  not  start  close  to  the  ground. 
Low  branching  is  correlated  with  an  early  opening  of  the  tips  in  the 
marketable  sprouts. 

Harvesting  and  Grading  Seed. — If  the  berries  are  harvested  before 
they  are  mature,  the  seed  will  shrivel  to  some  extent.  At  maturity 
the  selected  seed-bearing  plants  are  cut  and  laid  on  canvas,  and  the 
berries  removed  by  stripping  by  hand,  by  beating,  or  by  rolling.  The 
berries  may  be  placed  in  burlap  sacks  and  pounded  or  tramped  in 
order  to  break  the  berry  coats  and  free  the  seed.  This  mass  of 
material  is  then  placed  in  a  barrel  or  tank  of  water  and  stirred  well. 
The  seeds  will  settle  to  the  bottom,  and  the  lighter  material,  such  as 
skins,  pulp,  and  stems,  will  arise  to  the  surface  and  can  be  skimmed 
or  floated  off.  After  several  changes  of  water  the  seed  should  be 
spread  out  on  a  canvas  to  dry. 

After  the  seed  is  dried,  it  should  be  run  over  properly  meshed 
screens  and  graded  as  to  size.  The  practice  of  grading  is  strongly 
recommended. 


BULLETIN    381]  GROWING   AND    HANDLING   ASPARAGUS    CROWNS  9 

There  is  considerable  variation  in  the  weight  and  number  of  seed 
to  the  pound  in  different  lots  of  commercial  asparagus  seed.  Certain 
lots  of  seed  have  come  to  our  attention  which  contain  as  many  as 
28,000  to  the  pound,  and  others  which  have  approximately  19,000 
seeds  to  the  pound.  The  average  run  of  commercial  asparagus  seed, 
however,  has  about  22,000.  It  is  well  known  that  Mary  Washington 
seeds  are  of  larger  size  and  weight  than  those  of  any  other  variety. 
These  qualities  result  in  vigorous  seedling  development  and  large  one- 
year-old  crowns.  There  are  a  number  of  factors  which  influence  the 
size  of  seed.  Almost  every  lot  of  seed  may  be  improved,  however,  by 
careful  grading. 

SEED    TREATMENT 

Under  average  field  conditions  asparagus  seed  germinates  slowly. 
It  is  usually  from  two  to  six  weeks  before  the  plants  appear  above 
the  ground.  This  difference  depends  upon  the  temperature  and 
moisture  of  the  soil  and  the  depth  of  planting.  It  is  usually  a  week 
or  more  longer  before  the  young  plants  are  large  enough  to  be  visible 
in  the  rows  and  to  permit  cultivation.  As  a  result  of  this  slowness 
of  germination  and  the  inconspicuousness  of  the  young  plants,  a 
growth  of  weeds  may  obscure  the  rows,  and  thus  make  cultivation 
and  weeding  a  difficult  and  expensive  operation. 

Two  methods  have  been  used  to  overcome  the  difficulties  in  the 
asparagus  nurserj^  incident  to  the  slow  germination  of  the  seeds. 
These  are:  (1)  The  sowing  of  quick  germinating  seeds  such  as  those 
of  radishes  with  the  asparagus  seed.  The  radish  plants  soon  appear 
above  the  ground  and  the  rows  are  thus  marked  so  that  the  grower 
is  better  able  to  cultivate  between  them.  (2)  Soaking  the  asparagus 
seed  in  water  to  hasten  germination. 

The  first  method  has  not  been  practiced  in  the  large  nurseries  of 
California.  Soaking  the  seed  before  planting,  however,  is  practiced 
by  a  number  of  growers.  They  assert  that  the  plants  come  up  a 
week  or  more  ahead  of  those  from  unsoaked  seed.  Other  growers 
maintain  that  they  can  see  no  difference  in  the  rate  of  germination  of 
soaked  and  unsoaked  seed. 

Prior  to  the  work  of  Borthwick,*  of  the  California  Experiment 
Station,  there  had  been  no  carefully  controlled  experiments  to  deter- 
mine the  influence  of  various  treatments  upon  the  germination  of 
asparagus  seed.     Borthwick  conducted  tests  both  in  the  laboratory 


*  Borthwick,  H.  A.  Factors  Influencing  the  Eate  of  Germination  of  the  Seeds 
of  Asparagus  officinalis.  Univ.  of  Calif.  Publications,  Agri.  Exp.  Station,  Tech- 
nical Paper  No.  18,  Nov.,  1924. 


10  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

and  in  the  field,  repeating*  his  experiments  a  number  of  times.  The 
various  methods  which  were  employed  with  a  view  of  hastening  the 
germination  of  the  seed  were  abrasion,  and  soaking  in  acids,  alkalies, 
various  salt  solutions,  and  water  at  different  temperatures  and  for 
different  lengths  of  time.  The  only  method  which  gave  definite  and 
practical  results  was  that  of  soaking  in  water. 

In  the  laboratory  tests,  asparagus  seeds  were  soaked  at  various 
temperatures  from  71°  to  122°  F.,  and  for  different  periods  of  time, 
ranging  from  6  to  110  hours. 

The  seeds  may  be  soaked  for  a  period  of  at  least  nine  days  without 
danger  of  a  reduction  of  final  germination  if  the  temperature  does 
not  exceed  104°  F. 

The  quickest  germination  obtained  in  the  laboratory  followed 
soaking  for  4%  days  at  86°  F. 

Borthwick  also  made  a  number  of  field  tests  to  compare  with 
the  results  obtained  in  the  laboratory.  In  one  series  of  these  tests 
he  noted  that  sixteen  days  after  planting,  all  lots  except  those  soaked 
at  113°  F.  for  86  and  110  hours,  had  a  higher  percentage  of  seedlings 
above  ground  than  the  unsoaked  control.  Seeds  soaked  for  86  hours 
at  86°  F.  had  practically  as  many  seedlings  above  ground  at  the 
end  of  14  days  as  the  unsoaked  seed  had  at  the  end  of  21  days.  Under 
the  conditions  of  this  experiment,  the  most  rapid  germinations 
occurred  in  seeds  soaked  in  water  for  86  hours  at  86°  F.  and  62  hours 
at  100°  F. 

In  another  field  test,  the  seed  of  which  was  planted  in  much 
colder  soil  than  that  of  the  preceding,  it  was  found  that  in  several 
soaked  cultures,  the  number  of  sprouts  above  ground  on  the  thirty- 
third  day  after  sowing  exceeded  that  of  the  unsoaked  control  on  the 
fortieth  day.  Twenty-one  out  of  25  soaked  cultures  germinated 
sooner  than  the  controls.  Moreover,  the  final  germination  of  a  large 
number  of  soaked  cultures  as  recorded  on  the  fifty-first  day,  exceeded 
that  of  the  controls.  In  this  test  the  most  rapid  germination  occurred 
in  seeds  soaked  at  temperatures  of  86°  F.  and  95°  F.  for  96  hours. 

There  is  a  lack  of  uniformity  in  germination  results  in  the  field,  as 
compared  with  results  in  the  laboratory.  This  is  due  chiefly  to  differ- 
ences in  depth  of  planting  and  in  soil  moisture. 

Borthwick  shows  also  that  previous  soaking  at  the  higher  tempera- 
tures increases  the  rate  of  germination  even  if  the  seed  is  planted  in 
cold  soil.  For  example,  seeds  which  had  been  soaked  at  86°  F.  germ- 
inated  more  rapidly  than  seeds  soaked  at  68°  F.,  even  though  both 
Lots  were  germinated  at  68°  F. 


BULLETIN    381]  GROWING   AND    HANDLING   ASPARAGUS    CROWNS  11 

In  conclusion,  it  should  be  stated  that  soaking  asparagus  seed  in 
water  for  the  purpose  of  hastening  germination  will  be  of  value  only 
when  the  treated  seed  can  be  planted  in  moist  soil.  If  placed  in  dry 
soil,  and  left  there  for  even  a  day  before  water  is  brought  to  it  either 
by  rain  or  irrigation,  the  seed  will  lose  water  to  the  soil. 

Soaking  asparagus  seed  in  water  is  not  difficult.  The  temperature 
and  time  may  vary  considerably  without  danger  of  injury.  A  tem- 
perature of  86°  F.  to  95°  F.  for  4-5  days  is  recommended.  Soaking 
in  water  at  the  ordinary  temperatures  of  the  air  (70°-75°  F.)  for 
short  periods  of  time  has  comparatively  little  value. 

After  the  seed  is  removed  from  the  water,  it  should  be  spread 
out  thin  on  a  canvas,  moved  about  for  a  few  minutes  until  the  water 
disappears  from  the  surface,  and  then  planted  immediately.  The 
soaked  seed  will  be  hard  and  firm,  and  after  drying  for  a  few  minutes, 
may  be  planted  with  a  drill,  or  by  hand.  If  the  seed  is  dropped  by 
hand  in  the  furrows,  moist  dirt  should  be  drawn  over  it  and  firmed 
immediately. 

PLANTING    SEASON 

Early  planting  of  seed  is  advised  in  order  that  the  plant  may  have 
a  long  growing  season  during  which  to  develop  a  large  crown.  The 
date  of  planting,  however,  must  be  governed  largely  by  local  and 
seasonal  conditions.  On  the  peat  lands  of  the  Delta  region,  seed 
can  be  sown  in  late  February  or  March.  In  the  Imperial  Valley 
seeding  can  take  place  somewhat  earlier. 

VARIETIES 

The  varieties  which  are  giving  the  most  satisfactory  results  in 
California,  regardless  of  whether  the  crop  is  to  be  marketed  fresh 
or  to  be  sold  to  the  cannery,  are  Palmetto  and  Mary  Washington. 
The  latter  variety  has  been  bred  to  a  high  state  of  perfection,  and 
the  shoots  are  larger  on  the  average  than  those  of  any  other  variety 
grown  under  similar  conditions.  The  shoots  are  green  with  a  purple 
tinge.  The  buds  and  leaf  scales  remain  tight  against  the  shoot  for  a 
considerable  time,  making  it  an  ideal  variety  for  the  "green  grass" 
market.  The  branches  of  the  mature  plant  spread  less  than  those 
of  other  varieties ;  the  main  stem  grows  very  tall  and  in  time  bends 
over,  giving  a  plantation  of  mature  plants  of  Mary  Washington 
a  decidedly  different  appearance  from  that  of  other  common  varieties 
like  the  Palmetto,  Argenteuil,  and  Conover's  Colossal.  Mary  Wash- 
ington is  not  entirely  rust  resistant,  though  it  suffers  less  in  severe 
epidemics  of  rust  than  the  semi-resistant  varieties  such  as  Palmetto 
and  Argenteuil. 


12  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


SEEDING 

Bate  of  Seeding. — The  tendency  among  growers  in  California  has 
been  to  sow  the  seed  too  thick.  It  is  not  uncommon  to  plant  as 
much  as  20  pounds,  of  seeds  to  the  acre.  It  is  doubtful  whether  more 
than  10  pounds  is  ever  advisable.  Where  hand  cultivation  is  to  be 
practiced  seed  should  be  sown  in  rows  15-18  inches  apart.  Where 
horse  cultivation  is  to  be  practiced  usually  a  greater  distance  between 
the  rows  is  necessary.  It  is  best  to  drop  seeds  one  in  a  place  so  that 
the  plants  will  stand  about  three  inches  apart  in  the  row.  If  the  seeds 
are  dropped  in  groups  of  three  or  four,  fleshy  roots  and  rootstocks 
become  so  interwoven  that  it  is  difficult  to  separate  them  at  sorting 
time.  The  most  expensive  single  operation  in  connection  with  the 
present  method  of  producing  crowns  is  that  of  separating  the  different 
individuals  after  digging.  This  expense  can  be  greatly  reduced  by 
thinner  seeding.  Much  injury  is  often  clone  to  the  crowns  in  separ- 
ating them  when  they  are  grown  in  thickly  matted  rows. 

Methods  of  Planting. — The  seeding  is  usually  done  with  garden 
drills,  although  the  seed  is  sometimes  dropped  by  hand.  When  large 
acreages  are  planted,  the  drills  are  arranged  in  gangs,  and  two,  three, 
or  four  rows  are  sown  simultaneously.  A  number  of  growers  in  recent 
years  have  adopted  the  method  of  sowing  the  seed  in  furrows  3  to  6 
inches  wide  in  order  to  give  the  growing  plants  plenty  of  room  to 
develop  and  still  produce  a  large  number  of  crowns  to  the  acre.  This 
method  is  better  than  planting  too  thick  in  narrow  rows,  but  it  is 
unsatisfactory  on  foul  land,  as  a  great  deal  of  hand  work  is  necessary 
to  keep  the  rows  free  from  weeds. 

Where  surface  irrigation  is  practiced,  the  seed  is  usually  sown 
on  ridges  or  beds,  similar  to  those  used  in  the  growing  of  lettuce. 
If  the  spring  rainfall  is  plentiful  the  seed  can  be  sown  on  the  level, 
as  the  plants  will  be  large  enough  for  furrowing  between  the  rows 
by  the  time  irrigation  is  necessary.  It  is  best  to  sow  on  the  level  or 
on  low  beds  in  those  regions  where  strong  drying  winds  are  prevalent. 

Intercropping. — Companion  planting  and  intercropping  are  often 
practiced  in  the  production  of  nursery  stock.  Good  crowns  can  be 
produced  in  young  orchards  where  plenty  of  sunlight  is  available, 
but  the  young  asparagus  plants  will  not  do  well  in  the  older  orchards 
where  there  is  too  much  shade.  (See  fig.  12.)  Some  growers  raise 
nursery  slock  between  the  asparagus  rows  that  have  just  been  set  in 
the  permanent  field.  This  is  undoubtedly  an  undesirable  practice, 
especially  from  the  standpoint  of  the  permanent  bed.     The  seedlings 


BULLETIN    381]  GROWING   AND    HANDLING   ASPARAGUS    CROWNS 


13 


rob  the  soil  of  plant  food  that  is  needed  to  establish  the  transplanted 
crowns.  Moreover,  the  volunteer  crowns  which  remain  after  digging 
are  rather  hard  to  eradicate  for  a  year  or  two. 

Depth  of  Planting. — The  proper  depth  of  planting  varies  with 
the  type  of  soil.  In  peat  soils  the  seed  can  be  planted  2^4  to  3  inches 
deep.  There  is  little  advantage  in  deep  planting  except  to  keep  the 
seed  in  contact  with  a  permanent  moisture  supply  and  thereby  insure 
quick  germination.  In  sandy  loam  and  light  sandy  soils  the  seed 
should  be  planted  from  iy2  to  2  inches  deep. 


GERMINATION    OF    SEEDS 

Description  of  Berry  and  Seed. — The  asparagus  berry  usually  has 
three  seed  cavities.  As  a  rule  two  seeds  begin  to  develop  in  each 
cavity,  and  if  all  attain  maturity,  the  ripe  berry  will  have  six  seeds. 
The  actual  condition,  as  ascertained  by  counting  the  seeds  in  all  the 
berries  of  an  average  plant,  is  shown  in  the  following  brief  table. 


Number  of  seeds  to  the  berry 

l 

2 

3 

4 

5 

6 

7 

8 

Total 

Number  of  berries 

86 
6.3 

83 
6.1 

185 
13.8 

265 
19.7 

362 

26.8 

365 
27.0 

3 
0.2 

1 

0.1 

1,350 

Per  cent  total  number  of 
berries 

100 

From  this  it  will  be  seen  that  there  is  approximately  an  equal  per- 
centage of  berries  containing  five  or  six  seeds,  respectively.  And, 
considering  all  the  classes,  the  total  percentage  of  berries  having 
fewer  than  six  seeds  is  much  greater  (72.7  per  cent)  than  that  having 
six  seeds  to  the  berry  (27.0  per  cent).  A  great  number  of  seeds  fail 
to  attain  maturity  for  one  reason  or  another ;  and  an  examination 
of  mature  berries  often  reveals  the  presence  of  abortive  seeds.  One 
frequently  finds  plants  bearing  a  number  of  prematurely  red  berries 
which  are  much  undersized  and  contain  no  viable  seed. 

In  any  lot  of  asparagus  seeds,  it  will  be  observed  that  there  are 
two  quite  distinct  shapes,  as  shown  in  figure  1.  If  two  seeds  develop 
in  a  single  cavity,  the  surfaces  which  touch  become  flattened  because 
of  pressure.  However,  if  but  a  single  seed  develops  in  a  seed  cavity, 
and  consequently  is  not  crowded,  it  becomes  equally  rounded  on  all 
sides.  There  is  no  reason  to  believe  that  one  type  of  seed  is  superior 
to  the  other. 


14  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

The  asparagus  seed  has  three  essential  parts : 

(1)  The  seed  coat. 

(2)  The  embryo  plant  or  germ. 

(3)  The  endosperm  or  reserve  food. 

The  relationship  of  these  parts  is  shown  in  figure  2.  The  seed 
coat  consists  of  several  layers  of  cells,  the  outermost  of  which  has  a 
very  thick  black  wall  which  is  distinctly  roughened.  This  roughness 
can  be  easily  seen  with  a  hand  lens.  A  conspicuous  membrane  com- 
posed of  two  fatty  membranes  close  together  (fig.  3)  forms  the  inner 
boundary  of  the  seed  coat.  This  membrane  plays  a  very  important 
part  in  the  absorption  processes  carried  on  by  the  seed.  It  has  prop- 
erties which  enable  it  to  prevent,  either  totally  or  in  part,  the  entrance 
of  certain  salts  and  other  substances,  although  it  does  not  inhibit  the 
movement  of  water  through  it. 

The  embryo  plant  or  germ  is  a  very  small  slender  body,  somewhat 
curved  at  one  end.  In  the  mature  asparagus  seed,  the  embryo  is  very 
simple  in  structure,  and  apparently  has  not  attained  a  stage  of  develop- 
ment as  advanced  as  that  reached  by  the  embryos  of  wheat,  corn,  bean, 
and  many  other  plants  when  their  seeds  are  fully  mature.  At  one  end 
of  the  embryo  is  the  root  tip.  A  short  distance  behind  the  root  tip 
is  a  shallow  depression,  at  the  base  of  which  is  the  growing  point  of 
the  stem.  The  remainder  of  the  embryo,  and  by  far  the  largest  part, 
is  an  absorptive  organ.  This  organ  remains  in  contact  with  the 
endosperm  during  the  early  stages  of  germination,  absorbs  food 
from  the  endosperm  and  delivers  it  to  the  growing  root  tip  and  stem 
tip.  The  comparative  slowness  of  germination  of  asparagus  seed  may 
be  due  in  part  to  the  undeveloped  condition  of  the  embryo  in  the 
mature  seed. 

The  embryo  is  completely  embedded  in  the  endosperm.  The 
ends  of  the  embryo,  ^however,  have  very  little  endosperm  tissue  be- 
tween them  and  the  seed  coats.  The  hard  flinty  endosperm  constitutes 
a  reserve  food  supply.  There  are  two  kinds  of  food  stored  in  the 
endosperm  of  asparagus.  These  are  hemi-cellulose  and  fat.  Hemi- 
cellulose  is  a  carbohydrate  resembling  somewhat,  in  its  chemical  com- 
position, starch  and  ordinary  cellulose.  Hemi-cellulose  is  stored  in 
the  walls  of  the  endosperm ;  fat  occurs  as  droplets  in  the  cell  cavities. 
The  hardness  of  the  endosperm  of  the  asparagus  seed  is  due  to  hemi- 
cellulose  in  its  walls.     (See  fig.  3.) 

Germination  Processes. — When  the  seed  is  placed  under  conditions 
favorable  to  germination,  and  sufficient  water  has  been  absorbed, 
digestion  of  the  endosperm  begins.     In  this  process,  hemi-cellulose 


BULLETIN    381]  GROWING   AND    HANDLING   ASPARAGUS    CROWNS 


15 


MP 

.'V 


:V'-.'.;W-;ii.. . ' 


sit  -,,■_. 


;  /i'.'-.W.1;'-'   v.'* '..•'■  **  '"  ".     .  ..*t!E^C\^'S;v'V 

*^     -     t     ,  '' 


m*W?  ::■:'■■■:■■   «.  ■:■:.■ 


■■:■■■:■. -^x?~^i 


Fig.  1. — Two  shapes  of  asparagus  seeds  (top  view).  Left,  rounded  seed  from 
locule  which  bore  but  this  one  seed;  right,  seed  flattened  on  one  side,  from  locule 
which  produced  two  seeds,    a,  flattened  surface. 


seed  coat 


Fig.  2. — Diagrams  of  asparagus  seeds  showing  position  of  the  embryo. 

A.  Section  through  the  seed  showing  the  embryo  in  longitudinal  section. 

B.  Section  through  the  seed  showing  the  embryo  in  transverse  section. 


16 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


and  fat  are  changed  chemically  into  substances  which  can  move  from 
one  part  of  the  seed  to  another.  These  products  of  digestion  of  hemi- 
cellulose  and  fat  move  to  the  root  tip  and  stem  tip  of  the  embryo,  and 
growth  begins.  The  root  of  the  embryo  enlarges  and  after  a  time 
breaks  through  the  seed  coat.  After  it  has  attained  a  length  of  from 
one-fourth  to  one-half  an  inch,  the  stem  or  first  shoot  appears.  The 
absorptive  organ  of  the  embryo  remains  in  contact  with  the  endo- 
sperm for  several  weeks,  and  during  the  absorption  of  the  endosperm 


\  endosperm 


Fig.  3. — Section  of  a  portion  of  an  asparagus  seed,  showing  the  seed  coat  and 
the  large  cells  of  the  endosperm,  with  thick  walls  of  hemi-cellulose  ("reserve  cellu- 
lose"), and  cell  cavities  filled  with  oil  globules  and  protein  granules.  (Treated  18 
hours  with  2  per  cent  sodium  hydroxide  solution  in  order  to  swell  the  cells  of  the 
seed  coat.) 

it  increases  in  size,  finally  becoming  a  large  spongy  structure,  which 
may  almost  completely  fill  the  seed.  There  is  sufficient  reserve  food 
in  the  asparagus  seed  to  supply  the  young  developing  plant  for  an 
extended  period.  It  would  not  be  possible  to  plant  asparagus  seed 
at  the  usual  depth  of  2  to  3  inches,  if  it  were  not  for  the  large  amounts 
of  stored  food  in  the  endosperm,  and  the  maintenance  of  a  connection 
between  this  endosperm  and  the  growing  points  of  the  embryo  by  the 
special  absorption  organ.  The  first  shoot  of  the  asparagus  seedling 
receives  nourishment  from  the  seed  sufficient  to  enable  it  to  grow 


Bulletin  381] 


GROWING   AND    HANDLING   ASPARAGUS    CROWNS 


17 


through  from  3  to  5  inches  of  soil.  The  growth  of  the  primary  root 
also  depends  for  a  considerable  length  of  time  upon  the  supply  of 
food  in  the  endosperm. 

Conditions  Necessary  for  Germination. — The  requirements  for  the 
germination  of  asparagus  seed,  and  in  fact  of  all  seeds,  are  water, 
oxygen,  and  a  proper  temperature.  In  certain  experiments,  asparagus 
seeds  have  been  kept  in  water  for  three  months  without  showing  evi- 
dence of  germination.  However,  this  prolonged  soaking  in  water  at 
ordinary  temperatures  does  no  apparent  injury  to  the  seeds,  for 
when  they  are  removed  from  the  water  and  placed  under  conditions 
suitable  for  germination,  vigorous  sprouts  appear  within  a  few  days 
and  the  percentage  of  germination  is  normal.  Asparagus  seeds  sub- 
merged in  water  may  be  made  to  germinate  within  4  or  5  days,  if 
the  water  is  aerated  by  air  bubbling  through  it.  The  above  experi- 
ments point  to  the  conclusions  that  asparagus  seed  will  endure  long 
soaking  in  water  at  ordinary  temperatures,  which  means  that  aspara- 
gus seed  in  the  field  will  withstand  submergence  in  water  or  saturated 
soil  for  a  long  period — at  least  three  months.  However,  germination 
of  the  seed  will  not  result  unless  there  is  a  plentiful  supply  of  oxygen, 
such  as  occurs  in  a  soil  in  good  physical  condition. 

The  optimum  temperature  for  the  germination  of  asparagus  seed 
is  between  77°  and  86°  F.  At  68°  F.  germination  is  very  slow.  The 
rate  of  germination  of  asparagus  seed  at  various  temperatures  is 
shown  in  table  1.     (See  fig.  4.) 

TABLE  1 

Kate  of  Germination  of  Untreated  Asparagus   Seed  under  Controlled 

Temperatures  in  the  Laboratory 


Temperature 

Per  cent  germination  after: 

germinating 

chamber 
Degrees  F. 

3  days 

4  days 

5  days 

6  days 

8  days 

10  days 

12  days 

17  days 

50 

68 

0 
0 
0 
0 
0 
0 

0 
0 
25 
50 
5 
0 

0 

2 

65 

74 

0 

4 

84 

83 

16 

0 

0 

11 

98 

91 

31 

0 

0 
14 

0 

0 
27 

77 

86 

95 

55 

67 
0 

104 

0 

0 

Asparagus  seed  will  make  slow  progress  if  sown  in  a  soil  the 
temperature  of  which  is  near  68°.  F.  or  below. 

The  absorption  of  water  by  the  seed  at  temperatures  below  77°  F. 
is  very  slow,  as  is  seen  from  tables  2  and  3. 


18 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 


TABLE  2 

Rate  of  Water  Intake  by  Asparagus  Seeds  Soaked  at  Different  Temperatures 
(Percentage  increase  in  weight  is  based  on  the  original  air  dry  weight.) 


Temperature 
at  which  seeds  were 

Percentage  increase  ir 

i  weight  when  soaked: 

soaked 
Degrees  F. 

4  hours 

10  hours 

15  hours 

16  hours 

22  hours 

24  hours 

50 

11.7 

14  4 

64 

6.1 

6.1 

15.9 

27.6 

14.4 
15.8 
27.5 
36.5 

19.6 
21.2 
33.0 

38.4 

24.0 
27.0 
36.0 
38.9 

72 

86 

104 

TABLE  3 

Kate  of  Water  Intake  by  Asparagus  Seeds  Soaked  at  Temperatures  of 

64°  F.  and  86°  F. 

(Percentage  increase  in  weight  is  based  on  the  original  air  dry  weight.) 


Tempera- 
ture at 
which 
seeds  were 

soaked 
Degrees  F. 

Percentage  increase  in  weight  after  soaking: 

3 

hours 

9 
hours 

24 
hours 

33 

hours 

48 
hours 

54 
hours 

69 
hours 

93 

hours 

117 
hours 

142 

hours 

153 

hours 

164 
hours 

64 

5.4 
9.6 

13.2 
22.4 

28.7 
38.7 

34.5 
41.6 

40.2 

42.4 

41.1 

42.7 

42.6 
42.6 

43.2 
42.8 

43.3 
42.9 

43.6 
43.2 

43.5 

86 

43.4 

43.2 

Rate  of  Germination. — The  rate  of  germination  of  asparagus  seed 
depends  upon  water  and  oxygen  supply  and  upon  the  soil  tempera- 
ture. With  all  conditions  near  the  optimum,  the  root  breaks  through 
the  seed  coat  within  6  to  8  days  after  planting  and  within  10  or  12 
days,  the  first  shoot  appears.  The  time  required  for  the  shoot  to  reach 
the  surface  of  the  soil  depends  not  only  upon  the  supply  of  water  and 
oxygen,  and  upon  the  temperature,  but  also  upon  the  depth  of  plant- 
ing and  the  texture  of  the  soil.  The  sooner  the  shoot  reaches  the  light, 
becomes  green,  and  begins  to  manufacture  its  own  food,  the  greater 
are  its  chances  of  survival.  If,  however,  the  developing  seedling  must 
struggle  through  an  excessive  depth  of  soil,  or  one  in  bad  physical 
condition,  it  may  exhaust  its  food  supply  and  succumb  before  reach- 
ing the  surface. 


Bulletin  381]  GROWING  AND   HANDLING  ASPARAGUS  CROWNS 


19 


Fig.  4. — Showing  influence  of  temperature  upon  the  rate  of  germination  of 
asparagus  seed.  A,  seeds  germinated  at  68°  F. ;  B,  86°  F.  Trie  photographs  were 
taken  seven  days  after  placing  the  seed  in  the  germinating  oven.  Forty-eight 
per  cent  of  the  seeds  germinated  at  68°,  while  92  per  cent  germinated  at  86°, 
within  the  week's  time. 


20 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


DEVELOPMENT    OF    THE    PLANT    DURING    FIRST    SEASON    OF    GROWTH 

In  the  growth  of  the  seedling  the  single,  primary  root  takes  a 
direct  course  downward,  developing  numerous  thread-like  lateral 
rootlets.  The  chief  function  of  this  primary  root  with  its  laterals  is 
absorption.  It  seldom  attains  a  length  of  more  than  5  or  6  inches. 
It  is  much  more  slender  and  fibrous  than  the  storage  roots  which  de- 
velop later.  The  single  primary  shoot  takes  a  direct  course  upward, 
and  upon  reaching  the  light,  develops  a  few  side  branches  and  leaves. 
This  primary  shoot  seldom  attains  a  length  of  more  than  4  or  5  inches. 
Both  the  primary  root  and  the  primary  shoot  are  temporary  organs. 
They  wither  and  die  long  before  the  end  of  the  growing  season. 

The  developing  plant  maintains  its  connection  with  the  reserve 
food  supply  in  the  seed  for  a  long  period,  by  means  of  its  fleshy 
absorptive  organ.  The  primary  root  and  primary  shoot  attain  a 
length  of  3  to  4  inches  before  connection  with  the  reserve  supply  of 
food  in  the  seed  is  severed.  On  the  very  young  crown,  a  brown  scar 
may  be  observed  at  the  point  where  the  absorbing  organ  was  attached. 

Table  4  and  figs.  5  to  8,  inclusive,  show  the  method  of  development 
of  asparagus  plants  during  the  first  season  of  growth.  The  plants 
studied  were  grown  in  a  nursery  on  the  University  Farm  at  Davis. 
The  numerical  values  are  the  average  of  twenty  plants  taken  at 
random  from  the  nursery  on  each  date.  Throughout  the  season  there 
was  a  rapid  increase  in  the  number  of  storage  roots,  but  a  less  rapid 
increase  in  the  number  of  secondary  shoots.  By  the  end  of  July,  both 
the  primary  shoot  and  the  primary  root  had  ceased  to  function. 


TABLE  4 

Development  of  Asparagus  Plant  During  First  Season 

(Numerical  values  are  the  average  of  twenty  plants.) 

(Seeds  planted  March  24,  1923.) 


Date  of  observation 


April  27 

May  19 

June  9 

June  30 

July  24 

August  13 

September  20. 


Length  of 

primary 

shoot  above 

the  seed 

(inches) 

Length  of 
primary 

root 
(inches) 

Number 

storage 

roots 

Maximum 
length 
storage 

roots 
(inches) 

Number 

secondary 

shoots 

3.0 

4.1 

0 

0 

0 

3.8 

5.1 

1.6 

0.2 

1.2 

4.0 

5.2 

4.1 

5.5 

2.1 

4.2 

5.4 

6.4 

7.5 

3.7 

4.3 

5.4 

16.1 

18.6 

5.5 

* 

* 

28.3 

8.1 

* 

* 

42.0 

9.0 

Maximum 
length 

secondary 
shoots 
(inches) 


0 

1.1 

5.7 

7.6 

12.1 

20.2 

24.0 


*  Primary  shoot  and  primary  root  withered.     The  seedling  was  attached  to  the 
endosperm  on  April  27,  but  on  all  subsefjuetii  dates  it  was  free  from  the  endosperm. 


BULLETIN    381]  GROWING   AND    HANDLING   ASPARAGUS    CROWNS 


Fig.  5. — Five  stages  in  the  development  of  an  asparagus  seedling.  At  the  left 
a  very  young  stage  showing  the  short  seminal  root  and  the  much  shorter  seminal 
shoot,  both  of  which  are  attached  to  the  seed  and  are  deriving  nourishment  from 
the  stored  food  in  the  endosperm.  In  the  second  and  third  stages  the  seed  is 
still  attached.  In  the  fourth  stage  the  plant  has  become  independent  of  stored 
food  in  the  seed,  the  seminal  shoot  has  branched  slightly,  a  second  shoot  has  arisen 
from  the  crown,  and  a  fleshy  root  has  developed.  In  the  fifth  stage  there  is  shown 
the  seminal  shoot,  two  well  developed  secondary  shoots  and  one  very  short  second- 
ary shoot.  The  following  are  the  dates  of  digging  and  the  ages  of  the  different 
seedlings:  (1)  April  3,  ten  days  after  planting  the  seed;  (2)  April  7,  fourteen 
days  after  planting  the  seed;  (3)  April  27,  thirty-four  days  after  planting  the 
seed;  (4)  May  19,  fifty-four  days  after  planting  the  seed;  (5)  June  9,  seventy-five 
days  after  planting  the  seed. 


22 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Fig.  6. — Asparagus  plant  dug  June  30,  ninety  six  days  after  planting  the  seed. 
The  slender  seminal  root  may  be  distinguished  from  the  more  fleshy  storage  roots. 
The  seminal  shoot  is  seen  at  the  left. 


BULLETIN    381]  GROWING   AND    HANDLING   ASPARAGUS    CROWNS 


23 


Fig.  7. — Asparagus  plant  taken  from  the  nursery  July  24,  one  hundred  and 
twenty  days  after  planting  the  seed.  Note  the  small  seminal  shoot  at  the  left. 
Compare  with  Fig.  6. 


24 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Each  new  shoot  which  arises  on  the  crown  during  the  first  year  is 
almost  always  larger  than  the  one  preceding.  This  condition  is  shown 
in  the  following  measurements  of  the  lengths  of  shoots  appearing  suc- 
cessively on  two  representative  plants.  It  may  also  be  seen  in  figures 
5  to  8,  inclusive. 

PLANT  No.  I. 


Order  of  development  of  shoot 

Length  when  mature,  in  inches 

Diameter  at  base,  in  inches 

Primary  shoot 

5 

withered 

First  secondary  shoot 

8.2 

.08 

Second  secondary  shoot 

9.0 

.10 

Third  secondary  shoot 

13.4 

.10 

Fourth  secondary  shoot 

19.7 

.16 

Fifth  secondary  shoot 

19.7 

.16 

Sixth  secondary  shoot 

25.2 

.19 

Seventh  secondary  shoot 

28.0 

.23 

The  eighth  and  ninth  secondary  shoots  at  the  time  this  record  was  made  were 
just  through  the  ground.  The  seventh  secondary  shoot  was  the  first  to  produce 
flowers. 

PLANT  No.  II. 


Order  of  development  of  shoot 

Length  when  mature,  in  inches 

Diameter  at  base,  in  inches 

Primary  shoot 

5 

.08  (withered) 

First  secondary  shoot 

6.6 

.10 

Second  secondary  shoot 

14.0 

.10 

Third  secondary  shoot 

16.5 

.10 

Fourth  secondary  shoot 

24.4 

.16 

Fifth  secondary  shoot 

25.2 

.16 

Sixth  secondary  shoot 

26.7 

.16 

Seventh  secondary  shoot 

11.8  (immature) 

.16 

The  seventh  shoot  was  the  first  to  produce  flowers. 

This  larger  size  of  the  new  shoots  which  appear  successively  on  the 
lengthening  rootstock  is  probably  due  to  the  rapid  increase  in  the 
supply  of  food. 

The  rate  of  development  of  the  nursery  asparagus  plant,  through 
the  stages  just  described,  depends  much  upon  soil  conditions,  particu- 
larly upon  the  available  water  supply.  The  plants  are  very  responsive 
to  soil  moisture  variations.  (See  figs.  12  and  13.)  New  shoots  and 
new  roots  develop  in  rapid  succession  if  there  is  an  adequate  water 
supply.  Any  deficiency  in  the  available  water,  however,  is  readily 
reflect ed  in  retarded  growth  of  the  plants.  By  the  last  of  June  the 
mots  iti  the  plants  to  which  table  4  refers  had  penetrated  the  soil  to 
a  depth  of  7  inches  or  a  little  more,  and  by  the  last  of  July  they  had 
reached  levels  as  deep  as  18  inches. 


BULLETIN    381]  GROWING    AND    HANDLING   ASPARAGUS    CROWNS 


25 


Fig.  8. — Asparagus  plant  taken  from  the  nursery  August  13,  one  hundred  and 
forty  days  after  planting  the  seed.  Note  the  first  flower-bearing  stalk  (center). 
The  seminal  root  has  become  detached  and  the  primary  shoot  has  withered.  This 
plant  shows  very  strikingly  the  increase  in  height  and  diameter  of  the  shoots  as 
they  make  their  appearance  consecutively  throughout  the  season. 


26 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


SEX    EXPRESSION    IN    THE    NURSERY 

Under  California  conditions  asparagus  comes  into  flower  during 
the  first  season  of  growth  from  seed.  It  is  often  possible,  even  in  the 
nursery  before  the  flowers  appear,  to  distinguish  male  from  female 
plants.  The  latter  are  taller,  as  a  rule,  than  the  former  but  the  num- 
ber of  shoots  to  the  plant  may  be  fewer.  Male  plants  bloom  earlier 
in  the  season  than  female  plants.  Considering  the  population  as  a 
whole  in  the  early  season,  the  male  individuals  constitute  a  majority 
of  all  plants  in  bloom.  This  is  shown  in  the  following  table,  the  data 
of  which  were  taken  in  the  asparagus  nursery  at  the  University  Farm, 
at  Davis. 

TABLE  5 

Number  of  Male  and  Female  Plants  in  Bloom  on  Dates  Indicated 


Date 


July  2 

July  7 

July  11 

July  13 

July  16 

August  8.. 
August  10 
August  11 


Number  of 
plants  observed 


3,200 

4,200 

800 

5,700 

9,200 

800 

800 

400 


Number  of 
male  plants 


22 
31 
18 
202 
214 
89 
60 
26 


Number  of 
female  plants 


0 
0 
0 
0 

1 
11 

50 
24 


Number  of 

plants  without 

blossoms 


3,178 
4,169 

782 
5,498 
8,985 
700 
690 
350 


As  the  season  advances,  the  percentage  of  pistillate  plants  in  bloom 
increases. 


i   . !  I: 


THINNING 

It  is  doubtful  whether  thinning  is  practicable.  Seeding  should  be 
regulated  so  as  to  get  the  desired  stand  without  thinning.  The 
method  of  plant  development  makes  the  thinning  process  very  difficult. 
This  operation  must  be  performed  before  the  second  aerial  shoot  has 
appeared  and  before  the  development  of  the  fleshy  root  system  has 
begun .  After  the  fleshy  root  system  has  begun  to  develop,  the  shoot 
usually  breaks  off  at  the  crown  when  an  attempt  is  made  to  pull  the 
I  (hint.  Tf  the  crown  remains  in  the  soil,  shoots  again  appear  in  a 
few  days.  After  the  fleshy  roots  have  once  started  to  develop  the  only 
way  to  thin  is  to  dig  out  the  crown,  but  in  doing  this  there  is  danger 
of  injuring  adjacent  plants. 


BULLETIN    381]  GROWING   AND    HANDLING   ASPARAGUS    CROWNS  27 


Fig.  9. — Crown  of  asparagus  plant,  taken  September  20,  one  hundred  and 
seventy-eight  days  after  planting  the  seed.  From  table  4,  it  will  be  seen  that 
from  August  13  to  September  20  the  plant  produced  but  a  single  secondary  shoot. 
There  was,  nevertheless,  a  considerable  increase  in  the  number  of  storage  roots 
and  in  the  size  of  the  crown. 


Fig.  10. — Asparagus  nursery  near  the  end  of  the  growing  eea^on.     The  plants 
are  properly  spaced,  and  an  excellent  growth  has  been  obtained. 


28 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


IRRIGATION 

The  soil  about  the  developing  rootstock  and  fleshy  (storage)  roots 
must  be  kept  moist  if  the  best  development  is  to  be  obtained.  The 
fleshy  roots  will  not  elongate  in  dry  soil.  Fleshy  roots  that  have 
started  to  grow  in  moist  soil,  stop  elongating  when  the  soil  becomes 
dry.  Crowns  which  have  a  large  number  of  short  fleshy  roots  have 
usually  been  subjected  to  periods  of  drought.  The  entire  soil  zone 
occupied  by  the  fleshy  roots  and  rootstocks  must  be  kept  moist  if  the 
maximum  growth  is  to  be  obtained  the  first  year.  Water  should  not 
be  added,  however,  after  the  early  part  of  September.     If  the  soil  is 


Fig.  11. — Showing  one  method  of  surface  irrigation  of  asparagus  nursery.     The 
rows  of  plants  are  level  with  the  surface,  and  are  two  feet  apart. 


kept  moist,  new  shoots  continue  to  appear  as  long  as  the  temperatures 
are  sufficiently  high  for  growth  to  take  place.  Shoots  appearing  late 
in  the  fall  make  a  considerable  demand  upon  the  stored  food  in  the 
crown. 

CULTIVATION 

The  manner  of  cultivation  should  vary  with  the  type  of  soil  and 
the  method  of  planting.  In  weedy  fields  cultivation  is  often  necessary 
before  the  seedlings  appear  above  the  ground.  If  a  little  radish  seed 
has  been  drilled  in  with  the  asparagus  seed  the  rows  can  be  seen 
within  three  or  four  days.  Cultivation  may  be  started  as  soon  as  the 
rows  are  visible.     Hand  cultivation  with  a  wheel  hoe  is  usually  prac- 


Bulletin  381] 


GROWING    AND    HANDLING    ASPARAGUS    CROWNS 


29 


tised  where  the  rows  are  close  together.  Where  surface  irrigation  is 
practiced  it  is  necessary  to  cultivate  the  ground  after  each  irrigation 
just  as  soon  as  the  soil  can  be  worked.  In  case  of  horse  cultivation, 
care  must  be  taken  not  to  injure  the  fleshy  roots  and  rootstocks  by 
plowing  too  deeply  or  too  near  the  row,  especially  late  in  the  season 
after  the  roots  have  spread  through  the  soil  surface.  The  roots  spread 
from  the  rootstock  in  the  shape  of  a  cone.  They  are  nearest  the  surface 
where  thev  are  attached  to  the  rootstock. 


*i  % 


Fig.  12. — Asparagus  nursery  in  a  young  pear  orchard.  There  are  six  rows  of 
asparagus  between  each  two  rows  of  trees.  The  picture  also  shows  the  influence 
of  the  water  supply  upon  the  growth  of  asparagus  plants.  The  large  plants  occupy 
a  strip  of  soil  which  allows  water  to  seep  through  it  more  readily  than  other  por- 
tions of  the  orchard. 


DIGGING  THE  CROWNS 

Crowns  are  usually  plowed  out  during  the  late  fall  or  early  winter. 
The  tops  should  be  cut  with  a  mowing  machine  and  then  raked  and 
burned  so  they  will  not  interfere  with  the  digging  operation.  The 
crowns  can  be  turned  out  with  a  two-horse  mold  board  plow.  Another 
implement  that  has  proved  very  satisfactory  for  loosening  crowns  in 
the  nursery  is  a  U-shaped  knife  that  runs  under  the  mass  of  fleshy 


30 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


roots  and  straddles  the  row.  The  knife  at  the  bottom  should  be  6  or 
8  inches  wide  with  an  upward  tilt  toward  the  rear  which  will  have  a 
tendency  to  loosen  the  dirt  about  the  crowns  and  make  it  easier  to  lift 
them  from  the  soil.  The  latter  method  of  digging  is  especially  adapted 
to  rows  that  are  planted  far  apart,  in  which  case  a  large  part  of  the 
root  system  can  be  saved.  Whenever  possible,  the  fleshy  roots  should 
be  obtained  uninjured.  If  the  growing  point  of  the  fleshy  root  is  not 
injured  it  will  continue  to  elongate  after  planting  (fig.  14).  The 
fleshy  roots  continue  to  grow  and  elongate  year  after  year.  They  do 
not  die  back  unless  injured. 


rs  v.  • 


...      <%:J^i 


Fig.  13. — Asparagus  nursery.  Note  the  strip  running  through  the  center  of 
the  field,  in  which  the  plants  are  comparatively  well-developed.  The  thin  stands 
on  either  side  are  due  to  a  water  table  permanently  too  high.  This  view  and  that 
in  Fig.  12  emphasize  the  fact  that  asparagus  plants  are  very  sensitive  to  the  supply 
of  available  moisture. 


A  short-handled  six-tined  manure  fork  may  be  used  to  lift  the 
crowns  out  of  the  soil  and  shake  out  the  loose  dirt.  The  crowns  are 
then  thrown  in  windrows  or  small  piles  and  allowed  to  dry  for  an 
hour  or  so  before  they  are  hauled  from  the  field. 

When  hauled  from  the  field  the  crowns  should  be  placed  on  a  dry 
board  or  cement  floor  or  on  well-drained  ground.  The  best  storage 
temperature  is  about  40°  F.  They  can  be  stored  for  a  long  period  at 
much  higher  temperatures  if  the  atmosphere  is  dry.     If  the  crowns 


BULLETIN    381]  GROWING   AND    HANDLING    ASPARAGUS    CROWNS 


31 


Fig.  14. — A  vigorous  "  Number  1"  asparagus  crown,  taken  during  the  second 
season  of  growth.  Note  the  injured  root  tips,  Avhich  have  made  no  further  growth. 
Boot  tips  which  are  uninjured  in  digging  continue  growth.  The  fresh  white 
storage  roots,  from  which  arise  numerous  absorbing  roots,  stand  out  in  contrast 
with  the  older  and  darker  storage  roots  which  bear  fewer  absorbing  roots.  At 
points  marked  ' '  a ' '  in  the  photograph,  there  can  be  seen  the  line  of  demarcation 
between  two  successive  years '  growth  of  a  storage  root. 


32 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


become  moist  from  heating  or  from  rain  or  heavy  fogs  they  soon  start 
to  rot.  Hundreds  of  thousands  of  crowns  are  lost  each  year  because 
of  rotting.  The  fleshy  roots  contain  large  amounts  of  cane  sugar,  which 
is  an  excellent  medium  for  the  growth  of  mold  organisms.  Mold 
spreads  very  rapidly  in  the  presence  of  moisture  and  a  high  tempera- 
ture, such  as  often  exist  when  crowns  are  stored  in  large  piles.  The 
planting  of  crowns  that  have  been  stored  in  large  piles  and  that 
have  been  injured  by  molding  is  one  of  the  most  common  causes  of 
poor  stands  in  the  field.  The  buds  may  be  dead  even  though  the 
fleshy  roots  appear  sound  and  healthy.  In  more  severe  cases  both  the 
fleshy  roots  and  the  buds  may  be  dead. 

The  crowns  should  not  be  stored  where  they  are  subject  for  a  long 
period  to  desiccating  winds.  Though  crowns  will  stand  a  great  deal 
of  drying,  growth  response  is  much  more  rapid  when  they  are  not 
subjected  to  extreme  desiccation.  The  best  results  are  obtained  when 
the  interval  between  digging  and  planting  is  short. 

Some  tests  of  crown  desiccation  were  started  at  the  University 
Farm  in  1924  to  determine  how  much  growth  was  retarded  when  the 
crowns  were  dried  for  a  considerable  period.  Table  6  shows  the  date 
of  digging,  the  loss  of  weight  during  storage,  and  the  stand  at  various 
dates  after  planting. 

TABLE  6 

Delay  of  Growth  Caused  by  Root  Desiccation   (Variety,  Palmetto) 
(Loss  of  weight  in  stored  crowns.) 


Weight 

Weight 

of 

of 

Row 

Crowns 

crowns 

crowns 

Loss  in 

Set  in 

number 

dug, 

on 

on 

weight, 

field, 

date 

2/11/24, 
pounds 

3/27/24. 
pounds 

per  cent 

date 

25 

2/5/25 

52.00 

41.21 

20.7 

3/29/24 

55 

2/5/25 

47.00 

38.25 

16.49 

3/29/24 

85 

2/5/25 

49.00 

39.50 

20.60 

3/29/24 

Number  of  crowns  having  aerial  shoots  on: 


8/8/24 
118 
118 
118 


5/2/24 

5/7/24 

5/12/24 

5/20/24 

1 

16 

55 

94 

6 

26 

47 

93 

2 

8 

36 

79 

Crowns  were  stored  in  burlap  sacks  in  a  dry  room  subject  to  the 
same  temperature  fluctuations  as  the  outside  atmosphere.  There  were 
118  crowns  in  each  sack,  sufficient  to  plant  one  row.  The  crowns  were 
set,  in  the  permanent  bed  March  29,  1924,  after  being  exposed  to 
desiccating  conditions  for  a  period  of  53  days.  They  were  planted 
in  furrows  eighl  inches  deep  and  covered  with  about  two  inches  of 
soil.     Water  was  Ihen  run  in  the  furrows  over  the  crowns.     At  inter- 


BULLETIN    381]  GROWING   AND    HANDLING    ASPARAGUS    CROWNS  33 


Fig.  15. — Grades  of  crowns:  "Number  1,"  "Number  2,"  and  "Number  3." 
It  should  be  the  aim  of  the  grower  to  produce  "Number  1"  crowns  to  plant  in  the 
permanent  field. 


34  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

vals  a  count  was  made  of  the  crowns  having  aerial  shoots.  Table  6 
shows  that  the  starting  of  growth  in  the  desiccated  crowns  is  very  slow. 
Even  under  the  most  ideal  growing  conditions  it  was  34  days  before 
any  shoots  appeared  above  ground. 

SORTING    AND    GRADING    CROWNS 

While  in  storage  the  crowns  should  be  sorted  and  graded  (fig. 
15).  The  crowns  are  separated  in  order  to  facilitate  planting.  In  the 
sorting,  the  small  crowns  should  be  discarded  as  well  as  large  crowns 
that  have  a  large  number  of  small  buds.  Large  crowns  with  a  few 
buds  are  better  than  large  crowns  with  a  large  number  of  small  buds. 


STATION  PUBLICATIONS  AVAILABLE  FOE  FREE  DISTRIBUTION 


BULLETINS 


No.  No. 

253.   Irrigation   and    Soil   Conditions  in   the  346. 

Sierra  Nevada  Foothills,  California.  347. 

261.  Melaxuma    of    the    Walnut,     "Juglans 

regia."  348. 

262.  Citrus   Diseases   of   Florida    and    Cuba  349. 

Compared  with  Those  of  California. 

263.  Size  Grades  for  Ripe  Olives.  350. 
268.  Growing  and  Grafting  Olive  Seedlings.  351. 
273.   Preliminary  Report  on  Kearney  Vine-  352. 

yard  Experimental  Drain. 
2  75.   The  Cultivation  of  Belladonna  in  Cali-  353. 

fornia.  354. 

276.  The  Pomegranate.  357. 

277.  Sudan  Grass 

278.  Grain   Sorghums. 

279.  Irrigation  of  Rice  in  California.  358. 

280.  Irrigation  of  Alfalfa  in  the  Sacramento 

Vallev.  359. 

283.   The   Olive   Insects  of  California.  360. 

285.  The  Milk  Goat  in  California. 

286.  Commercial  Fertilizers.  361. 

287.  Vinegar  from  Waste  Fruits. 

294.    Bean    Culture  in   California.  362. 

298.   Seedless  Raisin  Grapes.  363. 

304.   A   Study  of  the   Effects  of  Freezes  on 

Citrus   in    California.  364. 

310.   Plum  Pollination. 

312.  Mariout  Barley.  366. 

313.  Pruning  Young  Deciduous  Fruit  Trees. 

317.    Selections   of   Stocks   in   Citrus   Propa-  367. 

gation. 
319.   Caprifigs  and  Caprification.  368. 

321.    Commercial  Production  of  Grape  Syrup. 

324.  Storage  of  Perishable  Fruit  at  Freezing  369. 

Temperatures.  370. 

325.  Rice  Irrigation  Measurements  and  Ex-  371. 

periments      in      Sacramento     Valley, 
1914-1919.  372. 

328.   Prune  Growing  in  California. 

331.   Phylloxera-Resistant  Stocks.  373. 

334.  Preliminary  Volume  Tables  for  Second-  374. 

Growth  Redwood. 

335.  Cocoanut    Meal    as    a    Feed    for   Dairy 

Cows  and  Other  Livestock.  375. 

336.  The    Preparation   of   Nicotine   Dust   as 

an  Insecticide.  376. 

339.  The  Relative  Cost  of  Making  Logs  from 

Small  and  Large  Timber.  377. 

340.  Control  of  the  Pocket  Gopher  in  Cali-  378. 

fornia. 

343.  Cheese  Pests  and  Their  Control. 

344.  Cold  Storage  as  an  Aid  to  the  Market- 

ing of  Plums. 


Almond  Pollination. 

The  Control  of  Red  Spiders  in  Decidu- 
ous Orchards. 

Pruning  Young  Olive  Trees. 

A  Study  of  Sidedraft  and  Tractor 
Hitches. 

Agriculture  in  Cut-over  Redwood  Lands. 

California  State  Dairy  Cow  Competition. 

Further  Experiments  in  Plum  Pollina- 
tion. 

Bovine  Infectious  Abortion. 

Results  of  Rice  Experiments  in   1922. 

A  Self-mixing  Dusting  Machine  for 
Applying  Dry  Insecticides  and 
Fungicides. 

Black  Measles,  Water  Berries,  and 
Related  Vine  Troubles. 

Fruit  Beverage  Investigations. 

Gum  Diseases  of  Citrus  Trees  in  Cali- 
fornia. 

Preliminary  Yield  Tables  for  Second 
Growth  Redwood. 

Dust  and  the  Tractor  Engine. 

The  Pruning  of  Citrus  Trees  in  Cali- 
fornia. 

Fungicidal  Dusts  for  the  Control  of 
Bunt. 

Turkish  Tobacco  Culture,  Curing  and 
Marketing. 

Methods  of  Harvesting  and  Irrigation 
in  Relation  to  Mouldy  Walnuts. 

Bacterial  Decomposition  of  Olives  dur- 
ing Pickling. 

Comparison  of  Woods  for  Butter  Boxes. 

Browning  of  Yellow  Newtown  Apples. 

The  Relative  Cost  of  Yarding  Small 
and  Large  Timber. 

The  Cost  of  Producing  Market  Milk  and 
Butterfat  on  246  California  Dairies. 

Pear  Pollination. 

A  Survey  of  Orchard  Practices  in  the 
Citrus  Industry  of  Southern  Cali- 
fornia. 

Results  of  Rice  Experiments  at  Cor- 
tena,    1923. 

Sun-Drying  and  Dehydration  of  Wal- 
nuts. 

The  Cold  Storage  of  Pears. 

Studies  on  the  Nutritional  Disease  of 
Poultry  Caused  by  Vitamin  A  De- 
ficiency. 


CIRCULARS 


No.  No. 

70.   Observations    on    the    Status    of    Corn  155. 

Growing  in  California.  157. 

87.  Alfalfa.  160. 

111.   The  Use  of  Lime  and  Gypsum  on  Cali-  161. 

fornia  Soils.  164. 

113.   Correspondence  Courses  in  Agriculture.  165. 
117.  The    Selection    and    Cost    of    a    Small 

Pumping   Plant.  166. 

127.   House  Fumigation.  ]67. 

129.   The  Control  of  Citrus  Insects.  170. 
136.  M elilotus    indica    as    a    Green-Manure 

Crop  for  California.  172. 

144.    Oidium  or  Powdery  Mildew  of  the  Vine.  173. 

151.  Feeding  and  Management  of  Hogs. 

152.  Some  Observations  on  the  Bulk  Hand-  174. 

ling  of  Grain  in  California.  178. 

154.   Irrigation   Practice   in   Growing  Small  179. 
Fruit  in  California. 


Bovine  Tuberculosis. 

Control  of  the  Pear  Scab. 

Lettuce  Growing  in  California. 

Potatoes  in  California. 

Small  Fruit  Culture  in  California. 

Fundamentals   of   Sugar    Beet   Culture 

under  California  Conditions. 
The  County  Farm  Bureau. 
Feeding  Staffs  of  Minor  Importance. 
Fertilizing  California  Soils  for  the  1918 

Crop. 
Wheat  Culture. 
The    Construction    of    the    Wood-Hoop 

Silo. 
Farm  Drainage  Methods. 
The  Packing  of  Apples  in  California. 
Factors    of    Importance    in    Producing 

Milk  of  Low  Bacterial  Count. 


CIRCULARS — (Continued) 


No. 

184. 
190. 
193. 
198. 
199. 
202. 

203. 
205. 
208. 

209. 
210. 
212. 
214. 

215. 
217. 

219. 
220. 
228. 
230. 

231. 
232. 

233. 
234. 

235. 

236. 


237. 

238. 
239. 

240. 

241. 

242. 
243. 

244. 


A  Flock  of  Sheep  on  the  Farm. 

Agriculture  Clubs  in   California. 

A  Study  of  Farm  Labor  in  California. 

Syrup  from  Sweet  Sorghum. 

Onion  Growing  in  California. 

County   Organizations   for   Rural   Fire 

Control. 
Peat  as  a  Manure  Substitute. 
Blackleg. 
Summary  of  the  Annual  Reports  of  the 

Farm  Advisors  of  California. 
The  Function  of  the  Farm  Bureau. 
Suggestions  to  the  Settler  in  California. 
Salvaging  Rain-Damaged  Prunes. 
Seed  Treatment  for  the  Prevention  of 

Cereal   Smuts. 
Feeding  Dairy  Cows  in  California. 
Methods   for    Marketing   Vegetables    in 

California. 
The  Present  Status  of  Alkali. 
Unfermented   Fruit  Juices. 
Vineyard  Irrigation   in  Arid  Climates. 
Testing   Milk,    Cream,    and    Skim   Milk 

for  Butterfat. 
The  Home  Vineyard. 
Harvesting    and    Handling    California 

Cherries  for  Eastern   Shipment. 
Artificial  Incubation. 
Winter  Injury  to  Young  Walnut  Trees 

during  1921-22. 
Soil  Analysis  and  Soil  and  Plant  Inter- 
relations. 

The  Common  Hawks  and  Owls  of  Cali- 
fornia   from    the    Standpoint    of    the 

Rancher. 
Directions  for  the  Tanning  and  Dress- 

of  Furs. 
The  Apricot  in  California. 
Harvesting  and  Handling  Apricots  and 

Plums  for  Eastern  Shipment. 
Harvesting    and    Handling    Pears    for 

Eastern   Shipment. 
Harvesting  and  Handling  Peaches  for 

Eastern   Shipment. 
Poultry  Feeding. 
Marmalade  Juice  and  Jelly  Juice  from 

Citrus  Fruits. 
Central  Wire  Bracing  for  Fruit  Trees. 


No. 

245. 
247. 
248. 

249. 
250. 

251. 


252. 
253. 
254. 

255. 

256. 
257. 
258. 
259. 
260. 

261. 
262. 
263. 
264. 

265. 
266. 

267. 

268. 

269. 
270. 
271. 

272. 

273. 
275. 

276. 

277. 

278. 


Vine  Pruning  Systems. 

Colonization  and  Rural  Development. 

Some  Common  Errors  in  Vine  Pruning 
and  Their  Remedies. 

Replacing  Missing  Vines. 

Measurement  of  Irrigation  Water  on 
the  Farm. 

Recommendations  Concerning  the  Com- 
mon Diseases  and  Parasites  of 
Poultry  in  California. 

Supports  for  Vines. 

Vineyard  Plans. 

The  Use  of  Artificial  Light  to  Increase 
Winter  Egg  Production. 

Leguminous  Plants  as  Organic  Fertil- 
izer in   California  Agriculture. 

The  Control  of  Wild  Morning  Glory. 

The  Small-Seeded  Horse  Bean. 

Thinning  Deciduous  Fruits. 

Pear  By-products. 

A  Selected  List  of  References  Relating 
to  Irrigation  in  California. 

Sewing  Grain    Sacks. 

Cabbage  Growing  in  California. 

Tomato  Production  in  California. 

Preliminary  Essentials  to  Bovine  Tuber- 
culosis Control. 

Plant  Disease  and  Pest  Control. 

Analyzing  the  Citrus  Orchard  by  Means 
of  Simple  Tree  Records. 

The  Tendency  of  Tractors  to  Rise  in 
Front;  Causes  and  Remedies. 

Inexpensive  Lavor-saving  Poultry  Ap- 
pliances. 

An   Orchard  Brush  Burner. 

A  Farm  Septic  Tank. 

Brooding  Chicks  Artificially. 

California  Farm  Tenancy  and  Methods 
of  Leasing. 

Saving  the  Gophered  Citrus  Tree. 

Marketable  California  Decorative 
Greens. 

Home  Canning. 

Head,  Cane,  and  Cordon  Pruning  of 
Vines. 

Olive  Pickling  in  Mediterranean  Coun- 
tries. 


